In the histopathology workflow, tissue samples can be cut or otherwise excised from a gross specimen, a procedure known as “grossing”. These (sub)samples then go through a number of processing steps in the laboratory, typically ending up as stained tissue sections mounted on glass slides. In a digital pathology workflow, these glass slides are then scanned into digital histology microscopy images. While the pathologist (a specialist physician) performs the microscopic image review, the grossing is frequently done by other staff, such as technicians, resident physicians or other pathologists. For an overview of grossing procedures, see Theory and Practice of Histological Techniques, John D. Bancroft, Elsevier Health Sciences, the content of which are hereby included by reference as if recited in full herein.
In histopathology, the connection between a respective gross (or “grossing”) specimen and corresponding histology slides can be of vital importance. A macroscopic examination is done for most specimens and diagnostic findings are documented. In order to relate to these findings during microscopic review, the location of the findings relative to a respective tissue specimen are often marked with colored dye during the grossing procedure. The dye is preserved in the tissue samples through the subsequent processing and shows up in the microscopic images of the tissue sections on the glass slides. The location of the cut in the specimen is also of high importance. Knowing both the macroscopic orientation and the location of the tissue section relative to the tissue specimen are particularly important when assessing margins. For example, if cancerous cells are found in a region close to a resection border, the risk is high that there are remaining cancerous cells in the patient. Thus, the relation between macroscopic and microscopic findings is important and often affects therapy and medical decisions such as therapeutic treatment selections for the patient.
To meet the informational need, the pathologist performing the microscopic review should be provided a description of the gross specimen. In the past, such information was in the form of a manually drawn sketch on paper or in the form of a digital photograph(s) of the specimen from a macroscopic camera. If there is such a macroscopic camera, it may operate with software that allows manual drawing of cuts and other annotations such as measurements on the gross image.
Unfortunately, manually entered physical or digital markings on the macroscopic images can be relatively cumbersome to make, especially in the wet and dirty environment of a grossing station, and they can be imprecise or subjective due to the manual nature of the marking. Furthermore, at the microscopic review, the pathologist is required to cognitively make the connections between the markings and the scanned slides and regions of the slides.